Changeable gear for bicycles



N0. 6|5,033. Patented Nov. 29, I898. F. E. MAXWELL.

- CHANGEABLE GEAR FOB BlGYCLl-IS.

(Application filed. Sept. 30, 1897.)

2 Sheets-Sheet l.

(No Model.)

6 HeZcFwTEJWQxWaZZ v N0. 6l5,033. Patented Nov. 29, I898. F. E. MAXWELL.

CHANGEABLE GEAR FOB BICYCLES.

(Application filed Sept. 30, 1897.)

(No Model.)

M 13y ry lforgeys,

THE NORRIS PETERS co wuoro-umo, WASHINGTON. n. c.

UNITED STATES PATENT OFFICE.

FLETCHER EDGAR MAXWELL, OF GARRETT, TEXAS.

CHANGEABLE GEAR FOR BICYCLES.

SPECIFICATION forming part of Letters Patent No. 615,033, dated November 29, 1898.

Application filed September 80,1897. Serial in. 653,628. (No model.)

To ttZZ whom it may concern.-

Be it known that I, FLETCHER EDGAR MAX- WELL, a citizen of the United States, residing at Garrett, in the county of Ellis and State of Texas,have inventeda newand useful Changeable Gear for Bicycles, of which the following is a specification.

This invention aims to improve that class of changeable-speed gearing designed for bicycles and machines of like nature, whereby they are adapted to be propelled with equal facility over rough, smooth, hilly, and level roads and surfaces, thereby adapting the machine for speed or power, according to the surface condition over which the machine is traveling.

One of the principal features of the invention is the provision of a changeable-speed gearing which will be durable, light, easy of operation, and at all times under the control of the rider, so as to be instantly shifted to secure speed or power, as required, the operating means being disposed so as to be out of the Way and not detract from the appearance of the machine or add materially to the weight thereof.

For a full understanding of the merits and advantages of the invention reference is to be had to the accompanying drawings and the following description.

The improvement is susceptible of various changes in the form, proportion, and the 111lnor details of construction'without departing from the principle or sacrificing any of the advantages thereof, and to a full disclosure of the invention an adaptation thereof is shown in the accompanying drawings, in which Figure 1 is an elevation of a bicycle of ordinary construction, showing the application of the invention. Fig. 2 is a central longitudinal section of the crank-hanger and the mountings for the crank-axle, the latter being in elevation and having parts broken away. Fig. 3 is a detail perspective view of the clutch-sleeve. Fig. 4 is an edge view of a drive-sprocket. Fig. 5 is a detail view in perspective of the shipper ring or band applied to the clutch-sleeve. Fig. 6 is a detail view of the shipper-bar, showing the spring connections between it and the shipper-lever. Fig. .7 is a detail view of what may be properly termed the shipper-lever. Fig. 8 is a detail view of the upper portion of the operating-bar and the means whereby it is directed in its movements and held in an adjusted position.

Corresponding and like parts are referred to in the following description and indicated in the several views of the accompanying drawings by the same reference characters.

The bicycle illustrated is of the safety pattern and is of usual construction, the rear or drive wheel being provided with differentsized sprocket-wheels at the ends of its hub to admit of the machine being propelled at different rates of speed upon turning the crank-axle at a given speed, as will appear more fully hereinafter.

The crank-axle 1 is mounted in the crankhanger 2 in the ordinary way and is provided at its ends with cranks 3, of well-known formation. The middle portion of the crankaxle is enlarged, as shown at 4, and supports a clutch-sleeve 5, slidingly mounted thereon and of greater length than the part 4 and disposed so as to have its end portions projecting beyond the raised portion 4 and overlap the joint formed between the contiguous parts .of'the said portion 4 and the reduced ends 6 of the hubs 7 of the drive-sprockets S. Pins .or keys 9 pass through openings formed in the part4 of the crank-axle, and their end portions enter longitudinal slots 10 in the sides of the clutch-sleeve 5, and these pins cause the clutch-sleeve and crank-axle to rotate in consonance, whereas the slots 10 permit of the said clutch-sleeve having a limited longitudinal movement upon the raised portion 4 of the crank-axle to gear the machine for speed or power.

The front or drive sprockets 8 are similarly constructed and are of different diameters and are loosely mounted upon the end portions of the crank-axle upon opposite sides of its enlarged portion 4, and the terminal portions 6 of their hubs 7 are reduced to correspond in diameter with the diameter of the enlarged part 4, so that the end portions of the clutch-sleeve may overlap and move freely thereon. The shoulder or offset formed at the inner end or base of the reduced portion 6 is notched, forming teeth 11, which correspond with the teeth 12 at the ends of the clutch-sleeve, and said teeth when in mesh cause the clutch-sleeve, the drive-sprocket clutched thereto, and the crank-axle to revolve in unison as one part. The drivesprockets are connected with corresponding sprockets of the drive wheel by sprocketchains 13,whereby motion is transmitted from the crank-axle to the drive-wheel in the manner well understood in machines of this class.

The clutch-sleeve is moved upon the crankaXle by the following instrumentalities: A band or ring 14isseated in a groove 15, formed annularly in the clutch-sleeve and is split, the ends bordering upon the cleft having cross-bars 16 formed therewith or applied thereto in any desired way, said cross-bars nnitedly forming a cross head to which a shipper-bar 17 is secured by means of screws or fastenings 1b, the latter passing through openings in the bar 17 and threaded openings 19 provided in the end portions of the crosshead when its component parts 16 are drawn together by means of a screw or fastening 20, passing transversely through registering openings in the parts 16. This part 14 constitutes a shipper ring or band and by being split can be readily fitted to the clutch-sleeve or removed therefrom when desired, the fastening 20 providing a ready means for the purpose. The threaded openings 19 are formed part way in the meeting faces of the cross-bars 16,and after the screws 18 have been tightened they are clamped by giving a final turn to the screw 20, which draws the cross-bars 16 closer together and binds the screws 18 in the openin gs 19, so as to prevent their accidental loosening and displacement. The shipper-bar has a rib or elevated portion 21 formed on its inner or rear side and of a size corresponding to the cross-head formed by the bars 16 when united, and this cross-head and rib operate in a longitudinal slot 22, formed in the crank-hanger, whereby provision is had for the longitudinal movement of the shipperbar 17 and clutch-sleeve, which is essential for changing the speed.

Lugs 28 are formed at the ends of the shipper-bar 17 and support a rod 24, upon which are mounted springs 25 upon opposite sides of the active end 26 of the shipper-lever 27, which is composed of a rod 28, extending parallel with the lower reach of the machineframe and journaled in clips 29, applied thereto, and having its front end pointed and obtaining a. bearing in the lower portion of the head-tube,an arm 30,proj ectin g from the front end of the rod 28, and an arm 26, formed by bending the inner or rear end of the said rod. A shoulder 31 is formed upon the lower or rear end of the rod 28 and engages with the lower clip 29 and prevents downward displacement of the shipper-lever, upward movement being prevented by the pointed end obtaining bearing in the head-tube. The arm 26 is apertured and receives the rod 24 and occupies a central posit-ion between the springs 25. The operating-bar 32 has pivotal connection at its lower end with the arm 30 and operates through a clip 33, applied to the top reach-bar near its front end, and has notches 3% at its inner side to engage with the inner end of an opening 35, formed in the clip 33, whereby the bar 32 and the clutch-sleeve are held in an adjusted position. A spring 36, secured at its ends to the outer side of the operating-bar 32, bears against the outer end of the opening 35 and holds the notched side of the said bar in engagement with the inner end of the opening 35 for the purpose stated.

Upon operating the bar 32 it is pressed laterally to disengage one of its notches 34 from the clip 33, and an upward pull or downward push serves to turn the rod 28 in its bearings and moves its bent end or arm 26 laterally, thereby imparting a longitudinal movement to the shipper-bar 17 and the clutch-sleeve connected therewith. Should the ends of the teeth 11 and 12 come together at the instant the clutch-sleeve is moved longitudinally, one or the other of the springs 25 will be compressed, and when the teeth of the clutchsleeve come in register with the spaces between the teeth of the drive-sprocket the spring 25, previously compressed, will expand and complete the movement of the clutch-sleeve, so as to bring the teeth into mesh, whereby the required drive-sprocket is clutched with the crank-axle in the mannerset forth. A reverse movement of the operating-bar 32 will shift the clutch-sleeve in an opposite direction and clutch the other drive-sprocket with the crank-axle, as will be readily understood. As illustrated, ball-bearings will be interposed between the relativelymovable surfaces of the rotating parts to reduce the friction to a minimum.

The drive-sprockets 8 are retained in place by nuts 37, which are screwed upon the threaded ends of the crank-axle in such a manner as not to bind the said drive-sprockets. Ball-bearings are provided between the relatively-rotatable parts and may be of any pattern, so long as they attain the desired end.

Having thus described the invention, what is claimed as new is 1. In a changeable-speed gear for bicycles and machines of like nature, the combination of a crank-hanger having alongitudinal slot, a crank-axle mounted in the crank-hanger and having an intermediate enlarged portion, drive-gears loosely mounted upon the end portions of the crank axle upon opposite sides of its enlarged part, a clutch-sleeve mounted upon the intermediate portion of the crank-axle to rotate therewith and slide thereon, and having clutch-teeth at its ends to intermesh with corresponding clutch-teeth of the drive-gears,a shipper-bar placed against the outer crank-hanger and overlapping the slot formed therein, and having connection with the clutch-sleeve, a rod supported at its ends by means of the shipper-bar, springs mounted upon said rod, and a shipper-lever under control of the rider and coming bctween the inner ends of said springs, substantially as set forth.

2. In a changeable-speed gear, thecombination of a crank-axle, drive-gears loosely mounted thereon, a clutch-sleeve secured upon the crank axle to rotate therewith and having a limited longitudinal movement thereon, a split ring or band seated upon the clutch-sleeve and having cross-bars at its separated ends which unitedly form a cross-head, a shipper-bar secured to the bars comprising the said cross-head, springs supported by the shipper-bar, and a shipper-lever having a portion passing between the inner ends of the said springs-substantially as and for the purpose set forth.

3. In a changeable-speed gear for bicycles and the like, the combination of a crankhanger having a longitudinal slot in a side, a crank-axle, drive-gears loosely mounted upon the crank-axle, a clutch-sleeve mounted to turn with the crank-axle and having a limited longitudinal movement thereon, a split ring seated upon the clutch-sleeve and having cross-bars at its ends which unitedly form a cross-head, a shipper-bar having a rib on its inner or rear side corresponding to the cross-head and jointly therewith operating in the aforesaid longitudinal slot of the crank-hanger, springs supported by the shipper-bar, and a shipper-lever having a portion coming between the inner ends of the springs, as and for the purpose set forth.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in 3 5 the presence of two witnesses.

FLETCHER EDGAR MAXWELL. Witnesses:

E. T. TYRA, J. F. HUDSPETH. 

